Endoscopes provide a number of advantages when used in minimally invasive surgical procedures allowing the physician to view the surgical area, whether by direct visualization (e.g. via an eyepiece) or via a video screen that displays image data picked-up by a video endoscope. In any event, it is critical that the physician be provided with a clear and unobstructed view of the area ahead of the endoscope.
One challenge faced with the use of endoscopes is positioning the endoscope into a tight or difficult to access areas within a body cavity. For example, it may be necessary to view an area inside an internal organ, which requires the endoscope to be repeatedly bent or deflected. It is understood that it is highly undesirable to impinge upon the internal organ with the endoscope so as not to damage the surrounding tissue. This can become especially challenging when the endoscope must be deflected at a severe angle.
Accordingly, flexible endoscopes have been in use for some time. However, the flexibility and control of known endoscopes is limited. For example, it may be desirable, depending upon the application and use, to bend only a portion of the endoscope shaft at a severe angle while maintaining the endoscope shaft relatively straight both ahead or behind the bent portion of the shaft. Alternatively, it may be necessary to severely bend the shaft in several opposing directions while maintaining a relatively straight shaft between the bent portions. Current systems to not allow adequate shaft flexibility and control for difficult to access areas to be viewed, while at the same time, providing a cost effective and relatively simple design.
A number of systems have, with limited success, sought to provide a flexible endoscope shaft having increased control. For example, U.S. Pat. No. 6,942,613 (“Ewers et al.”) discloses a method for placing an advancing a diagnostic or therapeutic instrument in a hollow body organ of a tortuous or unsupported anatomy. Ewers et al. teaches use of an “overtube” into which a colonoscope may be inserted. Ewers et al. uses electrical wires, which are positioned in tunnels that extend the length of the overtube. Upon application of an electrical current, the diameter of the tunnels contracts such that the wires come into contact with the inside of the tunnel surface causing the overtube to become rigid because the wire is not allowed to slip longitudinally with respect to the tunnel. While this provides some increased control, this device is separate from the scope that is used, which increases the size and the diameter of the device to be inserted into the cavity. For precise endoscopic procedures, this is unacceptable. Further, Ewers et al. does not allow for a contraction or expansion of the length of the endoscope shaft and, in fact, states that this feature is undesirable. (See, Col. 3, lines 21-24; Col. 4, lines 4-8.) In addition, Ewers et al. does not provide for specific control of one or more area of the shaft where the length of the shaft in a particular area may be altered or made more rigid.
U.S. Pat. No. 6,770,027 (Banik et al.) describes an endoscope apparatus that uses one or more electronically controlled actuators (e.g. electroactive polymer actuators) controlling the operation of the endoscope portion based on received control signals. However, Banik et al. is disadvantageously provided as a disposable or a single use device. (See e.g., Col. 2, lines 7-9 & 64-67; Col. 3, lines 4, 6, 9 & 13; Col. 4, lines 23-28; Col. 6, lines 41 & 50-51.) This disadvantageously means that the endoscope can not also be utilized as a standard mechanically flexible endoscope. In addition, Banik et al. due to among other things “single use economics”, uses “wireless interface chipsets” rather than “electrical connections.” However, power signals cannot be sent in a wireless format, and therefore, Banik et al. has resorted to providing a portable power source for providing power to the actuators. While having a relatively short-term use battery for a disposable system is feasible, providing a battery to power a non-disposable endoscope is highly undesirable as such a power source would dramatically increase the size and the weight of the device.
Accordingly, what is desired then is a flexible endoscope that may be used both as a mechanically deflectable endoscope and further uses a material that may change characteristics upon the application of a stimulus, such as, for example, and electrical current.
It is further desired to provide a flexible endoscope that is re-usable that employs a material that may change characteristics upon the application of a stimulus and that is relatively light-weight.
It is still further desired to provide a flexible endoscope that may be used both as a mechanically deflectable endoscope and uses a material that may change characteristics upon the application of a stimulus such that, the physician is provided specific control of one or more area of the shaft whether manually or by means of the change in material characteristics.
It is yet further desired to provide a flexible endoscope that is re-usable that employs a material that may change characteristics upon the application of a stimulus where the length of the shaft in a particular area of the endoscope may be altered or made more rigid.